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This article reviews the role of imaging, imaging characteristics and significance of individual imaging modalities as well as the newer imaging modalities in the evaluation of head and neck cancer. In the pretreatment evaluation, imaging is performed primarily to determine the stage of tumor and to look for an occult primary. It helps in obtaining tissue samples to establish the diagnosis, and treatment planning if radiotherapy is considered. Postsurgery and radiotherapy changes can be differentiated from residual or recurrent pathology on imaging. Imaging also plays an important role in assessing the response to treatment.

Non-ketotic hyperglycinemia (NKH) is an uncommon metabolic disorder with an autosomal recessive inheritance due to abnormal glycine metabolism. We present the pre-therapy and post-therapy magnetic resonance imaging, biochemical and clinical features of a child with NKH with manifestation in the early neonatal period. The initial diagnosis of NKH was made on the biochemical evidence of elevated cerebrospinal fluid (CSF) glycine levels and CSF: plasma glycine ratio. Pre-therapy magnetic resonance imaging revealed thinned out corpus callosum, intracranial hemorrhages, prominent ventricular system, few cystic changes in bilateral gangliocapsular region and abnormal T2 hyperintensities in the white matter. Magnetic resonance spectroscopy did not reveal glycine peak in our case. Post-therapy, there was clinical improvement and reduction in CSF glycine levels. In the follow up scan, myelination had progressed with residual leukomalacic changes and volume loss of white matter.

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This article reviews the role of magnetic resonance imaging (MRI) in the evaluation of lateral skull base lesions. Due to superior soft tissue resolution and multiplanar capability, MRI provides accurate information and exquisite anatomical detail. Thus, it guides the surgeon in proper preoperative planning regarding the approach of a lesion. MRI is also useful in post-treatment follow-up to assess the therapeutic response and to identify potential complications. We discuss the relevant anatomy, indications of MRI and MR pulse sequences used in the diagnosis of lesions of lateral skull base. Characteristic MRI findings of various lesions which help to arrive at a specific diagnosis as well as pitfalls of MRI which may confound the diagnosis are described. Newer MR pulse sequences enable image-guided surgery, which assist the surgeon intraoperatively, are briefly discussed. In summary, this article emphasizes the role of MRI in providing a specific answer to a clinical problem and its ability to guide the clinician for better management of patients.